freebsd stable - May 2018 - Re: 11-STABLE still livelocks under combined network & disk activity — patch from D7538 helps

My home server (and torrent box) is rather beefy (E3-1220v3, 16GiB RAM,
radiz5, SSD L2ARC), NIC is igb (I210).

 This server expieince live-lock when there is fast and large download
with multiple streams (some very popular large torrent). In this state
it is not accessible by SSH, USB is failed (UPS, mouse and keyboard are
flaky), existing ssh connection is not simply "slow" but almost
unusable: 1-2 keypresses PER MINUTE, etc.

 top(1) shows (with 1 "frame" per minute update) that 100% of CPU is
consumed by "intr{irqXXX: igb0:que X}" in this state, memory is really
low (less than 100MiB) and pmc-based stats shows, that it is very hard
lock congestion somewhere in memory subsystem.

 As soon as download is finished, everything become normal again.

 Please note, that it is 100Mb/s download at max, not 1Gb/s!

  I've tried to tune different sysctls and even tuned UDP buckets, but
it doesn't help.

 This problem could be solved by https://reviews.freebsd.org/D7538.
Maybe, it could be integrated to system?

 Or there are other solutions?

-- 
// Lev Serebryakov

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On 5/22/2018 9:53 AM, Lev Serebryakov wrote:
>  This problem could be solved by https://reviews.freebsd.org/D7538.
> Maybe, it could be integrated to system?
> 
>  Or there are other solutions?
Hi,
	If you set vfs.zfs.arc_max to some value like 8G do you still
experience the problem ?

	---Mike



-- 
-------------------
Mike Tancsa, tel +1 519 651 3400 x203
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada